Radio receiving and sound reproducing apparatus



Oct. 19, 1954 J. B. BRADY RADIO RECEIVING AND SOUND REPRODUCINGAPPARATUS 2 Sheets-Sheet 2 Filed Dec.

INVENTOR Patented Oct. 19; 1954 UNITED STATES PATENT OFFICE RADIORECEIVING AND SOUND REPRODUCING APPARATUS John B. Brady, Somerset, Md.

Application December 5, 1952, Serial No. 324,293

10 Claims. 1

My inventionrelates broadly to radio receiving and sound reproducingapparatus and more particularly to a radio receiver and sound reproducerbuilt into a desk calendar stand.

This application is a continuation-in-part of my application Serial No.24,177, filed April 30, 1948, for Radio Receiving Apparatus, nowabandoned.

One of the objects of my invention is to pro vide a construction of acompact radio broadcast receiver built into the hollow base of a deskcalendar stand.

Another object of my invention is to provide a compact construction ofradio broadcast receiver assembled within the hollow base of a deskcalendar stand which encloses an electrical sound reproducer arranged toemanate sound vibrations through one wall of the desk calendar stand.

A further object of my invention is to provide a compact construction ofradio broadcast receiver installed within the hollow base of a deskcalendar stand of sheet metal construction, wherein the calendar standforms a capacity area constituting the antenna or radio frequencypick-up means for the radio broadcast receiver.

Still another object of my invention is to provide a construction ofsubstantially bifurcated chassis for the radio broadcast receiverhousing miniature electron tube assemblies, shaped to fit within theinverted pan base of a desk calendar stand.

A still further object of my invention is to provide a construction ofelectrical sound reproducer built into a desk calendar stand andutilizing the properties of the base of the desk calendar stand as anaid in the reproduction of tones through the sound reproducer.

Other and further objects of my invention reside in the arrangement andassembly of a miniature electrical sound reproducer and a miniatureradio broadcast receiver within the hollow base of a desk calendar standas set forth more fully in the specification hereinafter following byreference to the accompanying drawing, in which:

Figure 1 is a longitudinal sectional view through a desk calendar standshowing the assembly therein of a radio broadcast receiver embodyingminiature electron tube apparatus and circuit components and a miniatureelectrical sound reproducer, the view showing a fragmentary sideelevation of the desk calendar stand for illustrating the tuning controlextended exteriorly thereof; Fig. 2 is a plan view looking at theunderside of the desk calendar stand and showing'the electrical soundreproducer and the radio broadcast receiver installed therein; Fig. 3 isa view of the rear of the desk calendar stand showing the externalappearance of the grill work through which the sound emanates from theminiature electrical sound reproducer within the base; Fig. 4 is atransverse sectional View taken substantially on line 44 of Fig. 2; Fig.5 is a schematic view illustrating the electrical connection of theradio broadcast receiver with the electrically conductive sheet materialforming the calendar stand, where the calendar stand constitutes thecapacity area comprising the antenna of the radio broadcast receiver;Fig. 6 is a vertical cross-sectional view through a desk calendar standutilized as an electrical sound reproducer in accordance with myinvention; Fig. 7 is a horizontal sectional view taken substantially online 11 of Fig. 6; Fig. 8 is a vertical sectional view takensubstantially on line 8--8 of Fig. 6; Fig. 9 is a fragmentary top planview of the electrical sound reproducer installed in the desk calendarstand, certain of the parts being shown in horizontal section; Fig. 10is a vertical sectional view taken substantially on line lit-H5 of Fig.6; and Fig. 11 is a fragmentary schematic View illustrating the mannerof establishing electrical connection with the sound reproducer Withinthe calendar stand through an impedance matching transformer installedwithin the calendar stand.

Referring to the drawings in detail, reference character I designatesthe metallic base of a desk calendar stand formed as an inverted pan,having a maximum height at the rear thereof designated at la, and aminimum height at the front thereof designated at lb. The calendar standhas an inclined plane surface ic thereon which serves as a support andmounting means for the multi-leaf calendar pad Id which is secured inposition by means of transverse binding plate 2 fastened by means ofadjustable screws 3 having finger-gripping heads 4 thereon and whichpass through the binding plate 2 and through the stack of calendarleaves id and through the screw-threaded strip 5 which extendstransversely of the calendar stand beneath the inclined plane supportingplate lc thereof. At the front of the calendar stand there is provided acompartment 6 in which there is disposed the rockable shelf i whichserves as a carrier for the stack of separate memoranda sheets 8. Thefront edge of the rockable shelf l projects beyond the front of thecalendar stand and is provided with a resilient friction drag edging 9,serving as a friction drag against the bottom sheet of the stack ofmemoranda sheets 8, thus facilitating individual withdrawal of memorandasheets as the rockable shelf is moved out of engaging position withrespect to the terminating front edge |e of the calendar pad supportingplate lc. The rockable shelf 1 has a rear edge portion 1a thereon whichis connected to a biasing spring ID to a lug If extending downwardlyfrom the calendar pad supporting plate lc.

The calendar pad stand thus described is the invention of Harold G.Davis, as set forth in Letters Patent 2,422,474 of June 17, 1947,Calendar Stand With Memoranda Paper Supply, and Letters Patent 2,425,925of August 19, 1947, Calendar Stand With Memoranda Paper Supply Device.

The calendar stand I is formed from electrically conductive material andis utilized in the radio receiving apparatus of my invention as a radiofrequency energy pick-up means or antenna.

The calendar stand is substantially insulated from ground by means ofsupporting feet of insulating material represented at H, |2, l3 and I4.The supporting feet I3 and I4 are mounted on a transversely extendingstrip l5 adjacent the rear of the calendar stand. The calendar stand isthus insulatingly supported with respect to the ground on any suitablysupporting surface H3.

The rear end of the calendar stand I is apertured as represented at H toreceive the grill work I8. Interiorly of the calendar stand andsubstantially aligned with the grill work |8 I provide an electricalsound reproducer which I have designated generally at H). soundreproducer is of miniature size and fits within the calendar base at themaximum dimensioned end |a thereof. The calendar base tapers from themaximum dimensioned end la to the minimum dimensioned end lb and servesin effect as a horn tending to direct sound waves forwardly and towardthe rear end of the calendar stand where all vibrations emanate throughthe open grill work I8. The sound reproducing diaphragm of theelectrical sound reproducer |9 directs sound vibrations outwardlythrough the grill work |8 of the calendar base. The electrical soundreproducer is connected by a flexible cable, designated at 20, to theoutput of a radio receiver mounted in chassis 2|. The chassis serves asa bafile displaced to the rear of the electrical sound reproducer in thetapered chamber formed by the pan constituting the calendar stand,directing the sound vibrations from the rear of the electrical soundreproducer outwardly through the grill work |8 of the calendar base inreinforcement of the sound vibrations emanating from the front of theelectrical sound reproducer. In the form of my invention illustratedherein, the tapered chamber extends behind the sound reproducer for adistance which is a multiple of the depth of the soiuid reproducer IS.The depth of the tapered chamber behind the rear of the electrical soundreproducer is approximately four times the depth of the sound reproducerl9. The radio receiver mounted in chassis 2| includes an electron tubeapparatus of miniature size in which all of the electrical components,including vacuum tubes, transformers, condensers, resistors, andimpedance devices, are of miniature construction to fit compactly withinthe container formed by chassis 2|. The chassis 2| is slotted throughouta central portion at 22 to clear the spring actuating device I 0 whichcontrols the operation of the rockable shelf 1. The chassis 2| thusprovides a pair of housing por- The electrical tions 23 and 24containing the components of the radio broadcast receiver which I havedesig nated as housed within the dotted line 25, in Fig. 4. The chassis2| is electrically insulated from the metallic wall of the calendarstand I by means of separators of insulation material, which I havedesignated at 23 and 29 between the side walls lg and UL of the calendarstand and the chassis 2|. The fastening screws 45 which pass through theside walls of the calendar stand for securing the radio receiver chassis2| in position enter the insulator separators 26, 21, 28 and 29 and notthe chassis 2| of the radio broadcast receiver, for insuring theelectrical isolation of the chassis 2| from the sheet metal of thecalendar stand.

To prevent grounding of the chassis to the underside of the calendar padsupporting plate |c, I provide limiting stops of insulation material 30and 3| fastened to the under surface of the inclined plane calendar padsupporting surface lc. These limiting stops of insulation material 30,3| have the form of a pair of longitudinally extending strips ofinsulation material which insure a positive space between the chassis 2|and the electrically conductive calendar pad supporting surface |c.

In Fig. 5 I have illustrated the electrical connection of the invertedpan metallic base i to the radio broadcast receiver within the chassis 2The coupling circuit for the radio broadcast receiver has beenillustrated as including primary inductance 32 coupled with secondaryinductance 33 connected with tuning circuit 34 which connects to theminiature electron tube system and circuit components constituting theminiature radio broadcast receiver. Primary coupling coil 32 isselectrically connected by conductor 35 with "the metallic sheetmaterial of the calendar stand whereby the calendar stand I serves as acapacity area or radio frequency energy collecting means insulated fromthe ground through supports l2, I3 and M. A separate ground connection36 extends through an insulating grommet 31 in the side wall lg of thecalendar stand and connects to an adjustable clip 38 which may beclipped to any suitable ground.

The power supply for the radio broadcast receiver is furnished throughflexible power line connecting cord 39 having power plug 49 connectedthereto adapted to be inserted in the standard -volt, GO-cycle A.-C.power supply receptacle. The flexible cord 39 extends through insulationgrommet 4| in the side wall lb of the calendar stand and connects to thepower supply rectifier and power supply circuits of the radio broadcastreceiver in chassis 2|. The tuning control for the radio broadcastreceiver represented at 34 is operated externally of the side wall ofthe calendar stand, as represented at 42 for adjusting the circuits ofthe radio broadcast receiver to respond to desired broadcast frequenciesand for operating the radio broadcast receiver over the broadcastfrequency range with reference to the calibrated scale 43 on the side ofthe calendar stand.

The antenna connection 35 of the radio broadcast receiver chassis 2|extends out from the chassis 2| in insulated relation thereto at 45 andis detachably connected to the transverse strip l5 by means ofdetachable eyelet lug 41 fastened by screw 48. This arrangementfacilitates the installation and removal of chassis 2| from the openbottom of the calendar stand for Servicing maintenance and replacementof burned-out tubes or other circuit components. Adequate lengths ofleads are provided in conductors 36 and 39 to permit removal of thechassis 2! from the open base for maintenance operations thereon, whilethe conductors 3% and 39 remain threaded through insulated grommets 49and 58 in the side wall lh of the calendar stand aligned with insulatedgrommets 31 and 4! in chassis 25. The cover of the chassis 2i is readilyremovable and replaceable to provide access to the radio receivingapparatus within the chassis.

An On and Off switch i l extends through the side wall of the calendarstand from chassis 2! for conveniently turning the radio broadcastreceiver on and off.

The radio broadcast receiver to all outward appearances is a deskcalendar stand containing the conventional annually renewable deskcalendar pad. The device is, therefore, attractive as an ofiiceappliance and is readily merchandiseable as a self-contained packageunit. In certain instances it may be desirable to include a dry cellpower supply within the base of the calendar stand in lieu of thellS-volt, (SO-cycle A.C. power supply connection hereinbefore described.

In Figs. 64.1 I have shown in more detail the manner in which theelectrical sound reproducer is mounted within the base of the deskcalendar stand I to secure all of the advantages of the tapered hollowbase and directing the sound vibrations through the grill work it at therear end of the calendar stand. I have shown the electrical soundreproducer l9 mounted as an assembly and readily insertable as aproduction unit through the under side of the open hollow base of thedesk calendar stand I. The unit is assembled on a transversely extendingstrip 5! which is secured to the opposite interior sides of the hollowbase i as represented at 52 and E3 and provides a support for the anglemembers 54 between which the electrical sound reproducer unit 55 isassembled. The selectrical sound reproducer unit consists of thecylindrical permanent magnet 56 having a hollow center in which thepermanent magnet core 5? is mounted by means of screw 58 which passesthrough the permanent horseshoe magnet 59. A plate Gil extends acrossthe permanent magnet 56 and across the holes of permanent magnet 59 andis centrally apertured for the passage of the bobbin supporting sleeve-BI extending from the sound reproducing elliptically frusto-conicaldiaphragm 62. The diaphragm till is supported at its periphery betweenrims 63 and 6d suitably secured to the rim of the diaphragm. The rims 63and t l are supported by vertically extending brackets 55 and 65 whichare fastened to the transversely extending strip 5!. The front of theconical-shaped diaphragm 62 has the rim 53 thereof aligned with thegrill work It while the rear of the diaphragm 52 is substantially freeof any obstruction so that sound waves propagated rearwardly from thediaphragm I52 follow a path represented generally at 61 through thefollow base of the desk calendar stand impinging upon the baffle-likestructure 5a formed by the rear of compartment 6 and the rear-edgeportion la of the rockable shelf 1 from which the sound waves arereflected in paths designated generally at 68 for reinforcing the soundwaves 69 emanating from the front of the diaphragm and directed. throughthe grill work 18.

The proportions respecting the effective depth of the sound reproducercompared with the depth of the chamber behind the sound reproducerheretofore pointed out to be in the ratio of 4 to 1 has been indicatedin Fig. '7 where the effective depth of the sound reproducer I9 isindicated as a: while the depth of the chamber behind the soundreproducer is indicated as 420. These proportions have been found tosustain the tones emitted at the grill work it at maximum efiiciency.

The cylindrical portion 6! of the sound reproducing diaphragm carriesthe winding 69 which operates within the intense permanent magneticfield established through permanent magnet 56 and core 5? for convertingthe electrical impulses supplied through primary winding 10, impedancematching transformer II and secondary winding '52 into sound vibrations.The electrical connections from winding 69 are supported by the surfaceof the diaphragm 62 from which flexible leads extend to the terminals ofsecondary winding 72. The connections to primary winding l0 extend to aterminal strip indicated generally at 73 secured to the under surface ofthe desk calendar stand. From the terminals on terminal strip 73, aconnection extends through flexible lead 74 passing through grommet 15to a position exteriorly of the desk calendar base terminating in a plug76. The plug may be engaged in a jack box mounted beneath the desk ortable and to which leads extend from an intercommunication circuit orbroadcast circuit for operation of the sound reproducer within the deskcalendar base.

The hollow base of the desk calendar stand is closed by a plate 1'!which is secured to the bottom of the compartment 6 and to thetransverse strip 5! and carries the feet ii, l2, l3 and it whichinsulate the structure from the supporting surface represented at it.The plate ll closes the hollow base providing the horn-like hollowchamber from which the sound waves are projected through the rear of thedesk calendar stand.

I have found the structures of my invention, as set forth herein,practical and efiicient in operation, and while I have described myinvention in certain of its preferred embodiments, I realize thatmodifications may be made, and I desire that it be understood that nolimitations upon my invention are intended other than may be imposed bythe scope of the appended claims.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is as follows:

1. Radio receiving apparatus including an antenna formed by a capacityarea, a miniature radio receiving apparatus and a miniature soundreproducer connected therewith, said capacity area being shaped toprovide a tapered relatively shallow substantially horizontallyextending casing increasing in section from one end to the other endthereof and enclosing said radio receiving apparatus and soundreproducer on substantially three sides thereof and forming a supporttherefor, said sound reproducer being mounted within the end of saidcasing which is of largest section with the front of said soundreproducer aligned with the wall of the largest section end of saidcasing and the rear of said sound reproducer directed toward thesmallest section end of said casing, said capacity area having aninclined plane calendar pad top supporting surface thereon, and meansfor insulatingly supporting said capacity area with respect to ground.

2. Radio receiving apparatus comprising an antenna formed by a metallicsheet shaped as an inverted substantially horizontally extendingrelatively shallow pan and tapering from a minimum section at one end toa maximum section at the other end and insulatingly mounted with respectto earth and forming a support, the external surface of said panextending in an inclined plane and forming a calendar pad support, aminiature chassis carrying radio receiving apparatus thereon and.mounted within but spaced from the interior of said metallic sheetforming the inverted pan, and a sound reproducer electrically connectedwith said radio receiving apparatus with the front of said soundreproducer aligned with the wall of the maximum section end of said panand the rear of said sound reproducer directed toward the minimumsection end of said pan and mounted within the end of the inverted panwhich is of maximum section and operative through the end of theinverted pan of maximum section for projecting sound vibrations.

3. In a radio receiving apparatus, a casing formed from electricallyconductive material shaped as a relatively shallow substantiallyhorizontally disposed inverted pan and tapered from a maximum altitudeat one end to a minimum altitude at the other end, and forming a planesupport for a calender pad on the top thereof, a miniature electricalsound reproducer mounted within said inverted pan in the end thereof ofmaximum altitude with the front of said sound reproducer aligned withthe wall of the maximum altitude end of said pan and with the rear ofsaid sound reproducer directed toward the minimum altitude end of saidinverted pan, a miniature radio receiving apparatus mounted within saidinverted pan and electrically connected with said sound reproducer, saidinverted pan being electrically connected with said radio receivingapparatus and constituting a collector of radio frequency energy, andmeans for electrically insulating said inverted pan with respect toearth.

4. A radio receiving apparatus comprising a calendar pad stand formedfrom electrically conductive material constituting an antenna and havingan inclined calendar pad top supporting surface extending from a maximumheight at one end of the stand to a minimum height at the other end ofthe stand and disposed in a substantially horizontally extending plane,a miniature electrical sound reproducer mounted within the maximumheight end of said stand with the front of said reproducer aligned withthe wall of the maximum height end of said stand and with the rear ofsaid sound reproducer directed toward the minimum height end of saidstand and operative for projecting sound vibrations through the end ofthe stand with the rear of said sound reproducer directed toward theminimum height end of said stand, a miniature radio receiving apparatusmounted within said stand and electrically connected with saidelectrical sound reproducer, an electrical connection from said radioreceiving apparatus to said stand whereby said stand operates as anantenna, and means for insulatingly supporting said stand with respectto the earth.

5. Radio receiving apparatus comprising a calendar pad stand formed fromelectrically conductive sheet-like material shaped in the form of arelatively shallow substantially horizontally extending pan taperingfrom a maximum height at its rear end to a minimum height at its frontend for supporting a calendar pad in inclined position, said pan beingapertured at its rear end, a sound reproducer mounted within said panand operative for projecting sound vibrations through the apertured rearend of said pan, with the front of said sound reproducer aligned withthe apertured rear end of said pan and the rear of said sound reproducerdirected toward the minimum height end of said pan, and a miniatureradio receiving apparatus having its input connected with said pan as anantenna and its output connected with said electrical sound reproducer.

6. A radio receiving apparatus comprising a calendar pad stand formedfrom electrically conductive sheet-like material including front andrear portions, side wall portions, and an inclined calendar pad topsupporting portion extending from a maximum height at the rear of saidstand to a minimum height at the front of said stand in a generallyhorizontal direction, a miniature radio receiving apparatus supported inelectrically insulated relation to the interior of said stand, saidradio receiving apparatus having an input circuit and an output circuitwith the input circuit thereof electrically connected with said calendarstand as an antenna, a miniature electrical sound reproducer mountedwithin said stand at the maximum height end thereof and operative toproject sound vibrations through the rear of said stand, with the frontof said sound reproducer aligned with the rear wall of said stand andthe rear of said sound reproducer directed toward the minimum height endof said stand, an electrical connection between the output of said radioreceiving apparatus and said electrical sound reproducer, and means forelectrically insulating said calendar stand with respect to earth.

7. In an apparatus of the class described, a tapered relatively shallowhollow base structure extending longitudinally in a generally horizontaldirection from an end section of minimum cross-sectional area to an endsection of maximum cross-sectional area, an electrical sound reproducermounted in the end section of maximum cross-sectional area in saidhollow base structure with the front of said sound reproducer alignedwith the maximum cross-section end of said hollow base structure, saidelectrical sound reproducer directing sound vibrations outwardly throughthe last-mentioned end section of said base structure with the rear ofsaid electrical sound reproducer directed toward the end section ofminimum cross-sectional area, said base structure forming a taperedchamber behind the rear end of said electrical sound reproducer, and aradio receiver chassis disposed within said tapered chamber spaced fromthe rear of said electrical sound reproducer and forming a bafiie forreflecting sound vibrations forwardly through the end section of maximumcross-sectional area in said base structure.

8. In an apparatus of the class described, a relatively shallow hollowbase structure terminating in a sheet delivery device at one end thereofwith a centrally extending spring member disposed between the sheetdelivery device and a position within said hollow base structure, and aradio receiver chassis mounted within said hollow base structure, saidchassis having a central slot therein fitting around said centrallyextending spring member and projecting on both sides of the central slotin said chassis.

9. In an apparatus of the class described, a relatively shallow hollowbase structure termimating in a sheet delivery device at one end thereofwith a centrally extending spring member disposed between the sheetdelivery device and a position within said hollow base structure, and aradio receiver chassis mounted within said hollow base structure, saidradio receiver chassis having a central portion and a bifurcated portionwith the bifurcated portion fitting around said centrally extendingspring member.

10. In an apparatus of the class described, a relatively shallow hollowelectrically conductive base structure terminating in a sheet deliverydevice at one end thereof with a centrally extending spring memberdisposed between the sheet delivery device and a position within saidhollow base structure, and a chassis for electrical ap- 10 paratusinsulatingly supported within said hollow electrically conductive basestructure, said chassis having a central portion and a bifurcatedportion with the bifurcated portion fitting around said centrallyextending spring member.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,785,377 DeForest et a1. Dec. 16, 1930 1,843,524 Stenger Feb.2, 1932 1,847,456 Weinberger et a1. Mar. 1, 1932 2,062,632 Amdur Dec. 1,1936 2,189,455 Tyzzer Feb. 6, 1940 2,337.213 Topping Dec. 21, 1943

